|Scientific findings from Explorer VI - United States. National Aeronautics and Space Administration. Scientific and Technical Information Division|
Keywords: Astrodynamics; Geophysics; Cosmic physics
|Radio-frequency performance of an 85-ft ground antenna - X-band - Bathker, D. A|
Superhigh frequency performance of paraboloidal ground antenna for Deep Space Instrumentation Facility
Keywords: CONSTANTS; ORBIT CALCULATION; SPACE NAVIGATION; TRAJECTORY ANALYSIS; ASTRODYNAMICS; ORBITAL ELEMENTS; TABLES (DATA)
|Pressure Sensitive Paint Measurements on 15% Scale Rotor Blades in Hover - Wong, Oliver D.|
This paper describes a proof of concept test to examine the feasibility of using pressure sensitive paint (PSP) to measure the pressure distributions on a rotor in hover. The test apparatus consisted of the US Army 2-meter Rotor Test Stand (2MRTS) and 15% scale swept tip rotor blades. Two camera/rotor separations were examined: 0.76 and 1.35 radii. The outer 15% of each blade was painted with PSP. Intensity and lifetime based PSP measurement techniques were attempted...
Keywords: SPACE DEBRIS; COMPUTERIZED SIMULATION; ASTRODYNAMICS; EARTH ORBITAL ENVIRONMENTS; TRAJECTORY ANALYSIS; HYDRODYNAMICS; PARTICLE SIZE DISTRIBUTION; IMPACT VELOCITY
|Systems analysis research - NON|
Systems analysis research on radar range data revisions, variation of parameters method, and optimization of solar electric propulsion planetary orbiter
Keywords: AERODYNAMICS; SOLAR PHYSICS; STATISTICAL ANALYSIS; ASTRODYNAMICS; RESEARCH PROJECTS; ACOUSTICS; ATMOSPHERIC PHYSICS; CELESTIAL MECHANICS; FLIGHT MECHANICS; FLUID DYNAMICS; OPERATIONS RESEARCH
|Glass-Si heterojunction solar cells - Ahrons, R. W|
An increase in efficiency from 2% to over 7% was achieved by a solar cell that used polycrystal silicon heterojunction with SnO2 glass. For Single crystal substrates, efficiencies close to 10% were measured. These cells had the same structures as polycrystalline cells. Work on p/n heterojunction using In2O3 glass resulted in cells of 3% efficiency on polycrystalline material and 4% efficiency on single crystal material.
Keywords: COMPUTERIZED SIMULATION; DYNAMIC STRUCTURAL ANALYSIS; PROBLEM SOLVING; RIGID STRUCTURES; ASTRODYNAMICS; DEFORMATION; MATRICES (MATHEMATICS); MECHANICS (PHYSICS); SYSTEMS ANALYSIS
|Estimation of Cometary Rotation Parameters Based on Camera Images - Spindler, Karlhein|
The purpose of the Rosetta mission is the in situ analysis of a cometary nucleus using both remote sensing equipment and scientific instruments delivered to the comet surface by a lander and transmitting measurement data to the comet-orbiting probe. Following a tour of planets including one Mars swing-by and three Earth swing-bys, the Rosetta probe is scheduled to rendezvous with comet 67P/Churyumov-Gerasimenko in May 2014...
Keywords: MISSION PLANNING; LOW EARTH ORBITS; SWINGBY TECHNIQUE; ORBIT INSERTION; DEIMOS; TRAJECTORY ANALYSIS; ASTRODYNAMICS; SPACECRAFT PROPULSION; ASTEROIDS; NEAR EARTH OBJECTS; ECCENTRICITY; SPACECRAFT ORBITS; PERIHELIONS; SPHEROIDS
|Acoustic modal analysis of a full-scale annular combustor - Karchmer, A. M|
An acoustic modal decomposition of the measured pressure field in a full scale annular combustor installed in a ducted test rig is described. The modal analysis, utilizing a least squares optimization routine, is facilitated by the assumption of randomly occurring pressure disturbances which generate equal amplitude clockwise and counter-clockwise pressure waves, and the assumption of statistical independence between modes...
Keywords: AEROSPACE ENVIRONMENTS; EARTH (PLANET); MARS (PLANET); MERCURY (PLANET); SUN; VENUS (PLANET); ASTRODYNAMICS; ELECTROMAGNETIC RADIATION; GRAVITATION; PLANETARY SURFACES; PLASMAS (PHYSICS); SATELLITE SURFACES; SOLAR WIND; ATMOSPHERIC PHYSICS
|Dynamical Approach Study of Spurious Steady-State Numerical Solutions of Nonlinear Differential Equations - Yee, H. C.|
The global asymptotic nonlinear behavior of 1 1 explicit and implicit time discretizations for four 2 x 2 systems of first-order autonomous nonlinear ordinary differential equations (ODES) is analyzed. The objectives are to gain a basic understanding of the difference in the dynamics of numerics between the scalars and systems of nonlinear autonomous ODEs and to set a baseline global asymptotic solution behavior of these schemes for practical computations in computational fluid dynamics...
Keywords: CARBON STARS; EMISSION SPECTRA; EMISSIVITY; STELLAR EVOLUTION; STELLAR ENVELOPES; NUCLEATION; INFRARED ASTRONOMY SATELLITE; DUST; CONTINUUMS; EMISSION; POLYCYCLIC AROMATIC HYDROCARBONS; PLANETARY NEBULAE; HYDROCARBONS; EVOLUTION (DEVELOPMENT); C BAND; ASTRODYNAMICS; ASTROPHYSICS
|Single-Specimen Technique to Establish the J-Resistance of Linear Viscoelastic Solids with Constant Poisson's Ratio - Gutierrez-Lemini, Danto|
A method is developed to establish the J-resistance function for an isotropic linear viscoelastic solid of constant Poisson's ratio using the single-specimen technique with constant-rate test data. The method is based on the fact that, for a test specimen of fixed crack size under constant rate, the initiation J-integral may be established from the crack size itself, the actual external load and load-point displacement at growth initiation, and the relaxation modulus of the viscoelastic solid, w...
Keywords: MODELS; CHAINS; ERRORS; FREE VIBRATION; HELICOPTERS; MOMENTS OF INERTIA; NOISE REDUCTION; DESIGN ANALYSIS; GEARS; MANUFACTURING; NUMERICAL ANALYSIS; STRUCTURAL DESIGN; AIRCRAFT ENGINES; ASTRODYNAMICS; AUTOMOBILES
|MIT 16.346 Astrodynamics, Fall 2008 - MIT OpenCourseWare|
This course covers the fundamentals of astrodynamics, focusing on the two-body orbital initial-value and boundary-value problems with applications to space vehicle navigation and guidance for lunar and planetary missions, including both powered flight and midcourse maneuvers. Other topics include celestial mechanics, Kepler's problem, Lambert's problem, orbit determination, multi-body methods, mission planning, and recursive algorithms for space navigation...
Keywords: space navigation; two body problem; boundary value problem; Kepler; astrodynamics; orbital transfer; satellite; hyperbolic orbits; planetary flybys; hypergeometric functions; flight guidance; three body problem; Clohessy-Wiltshire equation; Hodograph plane; Battin-vaughan formulation; atmospheric drag; disturbing function